Closed circuit breathing apparatus



p 1958 w. c. HAMILTON ETAL 2,852,023

CLOSED CIRCUIT BREATHING APPARATUS 2 Sheets-Sheet 1 Filed Nov. 6, 1956BY may,

#512 .q 7- 7-01045 rs,-

United States Patent '0 CLOSED crRcUrT BREATHING APPARATUS William C.Hamilton and Robert M. Bovard, Pittsburgh, Pa., assignors to Mine SafetyAppliances Company, Pittsburgh, Pa., a corporation of PennsylvaniaApplication November 6, 1956, Serial No. 620,686

Claims. (Cl. 128-203) This invention relaties to breathing apparatus,and more particularly to closed circuit apparatus provided with anauxiliary oxygen supply.

It is among the objects of this'invention to provide closed circuitbreathing apparatus which is small and compact, which operates at lowpressure, which is particularly adapted to emergency use, which isinexpensive,

which uses no valves or regulators, which employs both a self-generatingcanister and an auxiliary oxygen supply, which can be started inoperation instantaneously or more slowly, which is unalfected by ambienttemperatures, and which may remain in fully assembled condition untilready for use.

In accordance with this invention the breathing apparatus has a conduitfor both inhalation and exhalation. Connected to the end of the conduitopposite the end applied to the face is an inlet and outlet opening of abreathing bag, which receives air exhaled through the conduit and fromwhich such air is inaled. Disposed in the conduit in the path of the airis an air-purifying canister filled with material which removes carbondioxide and generates oxygen. Associated withthe conduit is a receiverfor a small high pressure oxygen cartridge. The receiver is connectedwith the inside of the conduit through a tubular fitting. The cartridgein the receiver can be opened by manually operable means to allow oxygentherefrom to enter the conduit. When the apparatus is not in use, thebreathing bag is held in a small compact bundle by means which can bereleased whenever desired and automatically when the oxygen cartridge isopened.

The preferred embodiment of the invention is illustrated in theaccompanying drawings, in which:

Fig. l is a side view of the breathing apparatus;

Fig. 2 is a fragmentary vertical section taken on the line 11-41 of Fig.l; and e Fig. 3 is a fragmentary front view of the apparatus, partly insection, after the oxygen cartridge has been opened and the breathingbag has been released.

Referring to Figs. 1 and 2 of the drawings, a flexible breathing tube 1is provided at its upper end with means for connection to the face ofthe user. This may be a mask, but preferably is simply a flange 2 whichfits behind the lips in a well-known manner. Dirt and moisture areprevented from entering the upper end of the tube when not in use by asuitable stopper 3. A lanyard 4 may be connected to the tube or someother part of the apparatus for supporting a conventional nose clamp 5.

The lower end of the breathing tube is clamped on a tubular flange 7projecting up around a central opening 8 in the cover 9 of a housing 10for an air-purifying canister 11. The canister contains a well-knownchemical 12 which will remove carbon dioxide from the exhaled breath ofthe user and generate oxygen to be inhaled by him. The canister hasflanged openings 13 in its opposite ends encircled by sealing gaskets 14which are pressed against the top and bottom of the housing when cover 9A 2,852,023 1C Patented Sept. 16, 1 958 joints 15. The bottom of thehousing is provided with a central opening 16, from which a short rigidcoupling tube 17 extends downward. Secured to the lower end of this tubeis the neck 13 of a flexible breathing bag 19. This neck forms acombined inlet and outlet opening for the bag. The breathing tube 1,canister housing 10 and coupling tube 17 form a conduit, through whichair flows back and forth between the mouth of the user and the breathingbag.

The side wall of coupling tube 17 is provided with a small opening 21,and a tubular fitting 22 has one end Welded to the side of the tube.This fitting extends radially away from the tube and has a passage 23through it communicating with the opening in the side of the adjoiningtube. The upper part of the fitting is provided with a vertical opening24 and supports a vertical receiver 26 for a high pressure oxygencartridge 27 of the Sparklet type. The lower end of the receiver istightly secured to the tubular fitting and is provided with a verticalopening 2% in line with opening 24. The receiver includes a knurled ring29 that is screwed onto its upper end for engaging the top of thecartridge and pressing its reduced lower enddown onto a sealing gasket30 encircling the opening in the lower end of the receiver.

The radial opening 24 in the tubular-fitting opens into the top of anenlarged portion of passage 23 therein and contains a cartridgeperforator 31 having a pointed upper end. The enlarged lower end of theperforator fits loosely within opening 24, so that there will besufiicient clearance for the passage of oxygen through that opening, andrestson the central portion of a plunger rod 32. The outer end of theplunger is slidably mounted in the outer end of the tubular fitting,where it is encircled by a packing gasket 33. A coil spring 34 encirclesthe plunger and urges it toward the coupling tube. The plunger projectsfrom the tubular fitting and can be pulled out" a certain distance by apull ring 35. When the rod is pulled out in this manner, the inclinedside of an integral collar 36 encircling the rod forms a cam surfacewhich pushes the perforator upward to cause it to penetrate the lowerend of the oxygen cartridge. The high pressure oxygen in the cartridgethen will escape down through the bottom of the receiver and into thetubular fitting and from there into the coupling tube.

is attached to the rest of the housing, such as by bayonet Anotherfeature of this invention is that theapparatus is rendered more compactwhen not in use by compressing the breathing bag into a small bundle.This is preferably done by folding the opposite side edges of the bagtoward each other and then rolling the'bag up into a compact roll. It isheld rolled up by a cord 37 attached at one end to the bottom of thehousing and removably supported at its opposite end by an L-shapedbracket 38 connected with the projecting end of the plunger rod in thetubular fitting. More specifically, this opposite end of the cord ispreferably provided with an enlargement, such as a head 39, which isheld up in a recess 41 in the bottom of the tubular fitting by the partof the bracket that extends along the bottom of the fitting. This lowerend of the bracket is provided with an open-end slot 42, in which thecord bead is supported. When ring 35 is pulled to cause the cartridge tobe punctured, the bracket is pulled away from the head to release thecord from the tubular fitting so that the bag will unroll. Since thereare cases, as will beexplained presently, where it may be desirable notto use oxygen from the cartridge, the housing end of the cord may besecured to a flexible tab 43 normally held in place by a button 44fastened to the housing. This tab can be pulled down to remove the cordfrom the button in order to release the bag while the bead end of thecord remains attached to the tubular fitting. i i

The. breathing apparatus described herein'canbe used in three diiferentways. If the air suddenly becomes contaminated, a person carrying theapparatus can hold his breath long enough to insert the breathing tubein his mouth, apply the nose clamp and pull ring to puncture the oxygencartridge and simultaneously release the breathing bag. The compressedoxygen will immediately fill the bag, so the user can start breathing atonce. By the time the oxygen is consumed, the: chemical in the canisterwill be generating oxygen. This manner of starting the apparatus canalso be used when the ambient temperature is so low that initiation ofthe chemical reaction in the canister would be retarded too long. On

the other hand, if there is not so much hurry about using the apparatus,the user will not need to use the oxygen cartridge but can pull tab 43to release the breathing bag and then Wait until the moisture in hisbreath has started the canister chemical producing oxygen. He will thenhave the cartridge oxygen in reserve for the third case, which occurswhen the chemical is exhausted before escape can be made from thevitiated atmosphere. In such a case he can open the cartridge to releaseoxygen that he can breath for a while longer.

Although this apparatus is intended primarily for emergency escapes andself-rescues, it also can be employed as an inexpensive trainingapparatus for use of self-contained breathing apparatus, without theexpense of costly long-service canisters. The apparatus may also be usedfor inspection or rescue work where the user requires only a few minutesworking time and where he has ready access to a respirable atmosphere,such as would be the case when working in tanks, manholes or holds. Thesize of the canister is such that it is good for about five minutes whenthe user is working or moving about. When he is not working or movingaround, the canister Will provide oxygen sufficient for fifteen ortwenty minutes use. The apparatus is compact and light weight andtherefore convenient to carry. The basic assembly is permanent andreusable and utilizes'an inexpensive, expendable replacement canisterand cartridge. The appaartus is not subject to freezing, and variationsin ambient temperatures have no effect on it.

According to the provisions of the patent statutes, we have explainedthe principle of our invention and have illustrated and described whatwe now consider to represent its best embodiment. However, we desire tohave it understood that, within the scope of the appended claims, theinvention may be practiced otherwise than as specifically illustratedand described.

We claim:

1. Emergency closed circuit breathing apparatus comprising a conduit forboth inhalation and exhalation, a breathing bag having a combined inletand outlet opening connected to one end of the conduit for receiving airexhaled through the conduit, said conduit being formed to receive anair-purifying canister in the path of said air, a receiver for a highpressure oxygen cartridge, a tubular fitting providing a passage betweenthe receiver and the inside of said conduit, releasable means normal- 1yholding the breathing bag compressed into a compact bundle, and manuallyoperable means for opening an oxygen cartridge in the receiver andsimultaneously releasing said bag-holding means.

2. Emergency closed circuit breathing apparatus comprising a conduit forboth inhalation and exhalation, a breathing bag having a combined inletand outlet opening connected to one end of the conduit for receiving airexhaled through the conduit, said conduit being formed to receive anair-purifying canister in the path of said air, a receiver for a highpressure oxygen cartridge, a tubular fitting providing a passage betweenthe receiver and the inside of said conduit, manually operable means foropening an oxygen cartridge in the receiver, and a cord .having one endsupported by said conduit and its opposite end detachably associatedwith said means and normally forming a loop holding the breathing bagcompressed into a compact bundle, whereby upon operation of said meansto open a cartridge the cord is released to permit the bag to expand.

3. Emergency closed circuit breathing apparatus comprising a conduit forboth inhalation and exhalation, a breathing bag having a combined inletand outlet opening connected to one end of the conduit for receiving airexhaled through the conduit, said conduit being formed to receive anair-purifying canister in the path of said air, a receiver for a highpressure oxygen cartridge, a tubular fitting providing a passage betweenthe receiver and the inside of said conduit, a. cartridge perforator,and an actuator carried by said fitting and movable across saidperforator, the actuator being provided with a cam surface for pushingthe perforator into an oxygen cartridge in said receiver to releaseoxygen.

4. Emergency closed circuit breathing apparatus comprising a conduit forboth inhalation and exhalation, a breathing bag having a combined inletand outlet opening connected to one end of the conduit for receiving airexhaled through the conduit, said conduit being formed to receive anair-purifying canister in the path of said air, a receiver for a highpressure oxygen cartridge, a tubular fitting providing a. passagebetween the receiver and the inside of said conduit, releasable meansnormally holding the breathing bag compressed into a compact bundle, acartridge perforator, and an actuator engageable with said perforatorfor pushing it into an oxygen cartridge in said receiver, said actuatorbeing operatively connected with said bag-holding means for releasing itwhen said perforator is pushed.

5. Emergency closed circuit breathing apparatus comprising a conduit forboth inhalation and exhalation, a breathing bag having a combined inletand outlet opening connected to one end of the conduit for receiving airexhaled through the conduit, said conduit being formed to receive anair-purifying canister in the path of said air, a receiver for a highpressure oxygen cartridge, a tubular fitting providing a passage betweenthe receiver and the inside of said conduit, a cord having one endattached to said conduit and its opposite end provided with anenlargement, and manually operable means for opening an oxygen cartridgein said receiver and including a member provided with an open-end slotnormally supporting said cord enlargement, the breathing bag normallybeing compressed into a compact bundle supported by said cord, and saidslotted member releasing the cord when said means is operated to open acartridge.

6. Emergency breathing apparatus according to claim 5, inwhich saidfitting is provided with a recess receiving said cord enlargement.

7. Emergency closed circuit breathing apparatus comprising a conduit forboth inhalation and exhalation, a breathing bag having a combined inletand outlet opening connected to one end of the conduit for receiving airexhaled through the conduit, said conduit being formed to receive anair-purifying canister in the path of said air, a receiver for a highpressure oxygen cartridge, a tubular fitting extending across thereceiver and having the inner end of its passage in communication withthe inside of said conduit, the outer end of said passage being closedand one side of the fitting being provided with an opening connectingits passage with the inside of said receiver, a cartridge perforatorloosely mounted in said opening, an actuator in said fitting passageprovided with a cam surface beside said perforator, and means for movingthe actuator across the perforator to cause said surface to push theperforator into an oxygen cartridge in the receiver to release oxygen.

8. Emergency closed circuit breathing apparatus according to claim 7, inwhich said actuator is a rod slidably mounted in the closed end of saidpassage and adapted to be moved lengthwise to cause said cam surface toengage the cartridge perforator.

9. Emergency closed circuit breathing apparatus comprising a conduit forboth inhalation and exhalation, a

breathing bag having a combined inlet and outlet opening connected toone end of the conduit for receiving air exhaled through the conduit,said conduit being formed to receive an air-purifying canister in thepath of said air, a receiver for a high pressure oxygen cartridge, atubular fitting extending across the receiver and having the inner endof its passage in communication with the inside of said conduit, theouter end of said passage being closed and one side of the fitting beingprovided with an opening connecting its passage with the inside of saidreceiver, a cartridge perforator loosely mounted in said opening, anactuator in said fitting passage provided with a cam surface beside saidperforator, means for moving the actuator across the perforator to causesaid surface to push the preforator into an oxygen cartridge in thereceiver to release oxygen, a retaining member connected with said meansand provided with an open-end slot, a cord in said slot having anenlarged end normally supported by said member, the opposite end of thecord being attached to said conduit so that the cord normally forms aloop holding the breathing bag compressed into a compact bundle, andsaid cord being released from said retaining member slot when saidactuator is moved by said means.

10. In emergency closed circuit breathing apparatus, a housing for anair-purifying canister, the top of the housing having an opening adaptedto be connected to a breathing tube, the bottom of the housing alsohaving an opening, a coupling tube extending down from said bottomopening and adapted to be connected to a breathing bag, the couplin tubebeing provided with a lateral inlet, a tubular fitting projectinglaterally from the coupling tube and having a passage communicating withsaid inlet, an oxygen cartridge receiver mounted on said fitting besidesaid housing and communcating with said passage, manually operable meanssupported by said fitting for opening a cartridge in the receiver toallow oxygen therefrom to enter the coupling tube, and a cord forming aloop adapted to receive a rolled-up breathing bag, with one end of thecord attached to said housing and its opposite end detachably connectedwith said manually operable means.

References Cited in the file of this patent UNITED STATES PATENTS1,144,812 Claren June 29, 1915 2,507,450 Millikan May 9, 1950 FOREIGNPATENTS 610,741 Germany Mar. 15, 1935

